Reciprocating internal combustion engines include at least one cylinder with a piston located therein. A cylinder head overlies an upper end of the cylinder, and a combustion chamber is defined within the cylinder between the cylinder head and an upper portion or crown of the piston. Each piston is pivotally connected to a so-called small end of a connecting rod by a piston pin or wrist pin, and an opposite big end of each connecting rod is connected to a crankshaft. The piston moves up and down in the cylinder by forces produced in the combustion chamber during the operating cycle of the engine. The up and down movement of the piston is transferred via the connecting rod to the crankshaft, which converts the reciprocating movement of the piston into rotational energy.
During operation of the engine, the piston crown is repeatedly exposed to the high temperatures and pressures produced within the combustion chamber. To maintain the piston crown within a suitable operating temperature range, oil from the lubrication system of the engine is oftentimes used to cool the piston crown. For example, some pistons include an annular cooling chamber that extends around a periphery of the piston. Cooling oil is introduced into the annular cooling chamber in a variety of ways, and is splashed against the interior surfaces of the cooling chamber by the reciprocal movement of the piston in a “cocktail shaker” action.